This invention concerns locks for cabinets, lockers, drawers, access panels and similar situations. Specifically the invention embraces an electronic cam lock that fits office furniture, usually metal and wood file cabinets and other furniture units with doors, panels or drawers.
Metal and wood file cabinets, desk and cabinet drawers, locker doors, access panels and doors, mail boxes, dispensers and other secure situations often utilize relatively simple lock mechanisms known as cam locks. Such cam locks may or may not involve a camming action. In some cases they move other mechanisms that are engaged with the door or drawer of the cabinet or engaged with other mechanisms that are linked to the door and drawer of the cabinet or multiple doors or drawers of the cabinet. In all cases except plungers, cam locks have a rotatable component at a back side. In one of the simplest forms, a cam lock on a cabinet door typically fits in a ¾ inch diameter D-shaped or double D-shaped hole and, at the back side of the cam lock cylinder unit, has a metal blade or arm called a cam that rotates when the key is turned, from a position disengaged from surrounding cabinet hardware to a position of engagement in a slot or behind a ledge of the surrounding cabinet hardware. Other locks, such as those for desk drawers, commonly referred as cabinet locks, involve a camming type action as the key and plug are rotated, and these are also referred to as cam locks herein. The rotation causes a cam or nipple to move a deadbolt linearly to a locking or unlocking position, or in the case of a spring loaded latch or deadlatch, the rotation causes the cam or nipple to move a latch or deadlatch to unlocking position and removing the key keeps the latch or deadlatch in the extended locked position. The term cam lock excludes door entry locks on commercial or residential buildings. Such locks are heavier-duty and more secure than cam locks, which are typically small (¾ inch hole receives them) and lighter-duty, as for office furniture.
Metal filing cabinets often utilize cam locks, but sometimes have a variation known as a plunger type lock in which a spring loaded plunger/lock cylinder located in the top horizontal margin of the cabinet, when pushed in, will lock all drawers. The use of a key releases the spring plunger to return to the outward position and unlock the drawers. These plunger locks are also referred to as cam locks herein, even though they have no rotatable member that locks and releases doors or drawers.
Locker and cabinet locks have included electronic locking devices, some of which utilized keypads and some of which utilized IButtons or other ID or non-volatile memory devices which work on contact to release the lock. See, for example, U.S. Pat. Nos. 5,894,277, 5,886,644, 6,655,180 and 6,791,450. The disclosures of all of these patents are incorporated herein by reference.
There is a need for a relatively simple, easily used, reliable and compact electronic lock, which may have a keypad but optionally operable by an electronic key or wireless device which may not require contact, or both, for situations in which typically cam, plunger and cabinet locks were employed, and capable of fitting into a small space in the cabinet to produce a low-profile and aesthetic appearance. This is an objective of the current invention described below.